In recent years, development of household robots such as pet robots has been actively carried out, and it is expected that a more practical household robot such as a household assistant robot will be put to practical use in the future. Since the household robot must be part of the household and coexist with humans, physical contact with humans is inevitable, and is thus required to be flexible in terms of safety.
To respond to such an issue, a controlling device is disclosed in Unexamined Japanese Patent Publication No. 10-329071 of patent document 1 as a background art for detecting a contacting force with a human that is applied to a robot arm, enhancing safety by making restoration force small when large force is applied to the arm, and ensuring operation accuracy by making the restoration force large when very small force is applied to the arm.
[Patent document 1] Unexamined Japanese Patent Publication No. 10-329071